From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D9A2F2F549F for ; Mon, 20 Oct 2025 09:27:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760952472; cv=none; b=Sgqf2g53EshGb22Duo+CpzPLAgtslCdeVsCoDKYYRGU0FtBquj9rHqkmizD+zn14vM8SCorZQTvK9plpykIAlf4RaLouChHevHnPex8NFIin9CZNP9oX13T3v1zGZ61adpezAiWe5vq5BYrJ8Pvt/HE/RTlRjESyzUlgeTKctJA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760952472; c=relaxed/simple; bh=dFyf69AmPulWJCNb9/HhNO+93AFGf8+/y+hPagOet7w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DBv5zXHzEjqB0CVEKEJAju1u5hZ0y+e+4G1HTsKWXOP7uMsdlItgYuD+TQs32lZsRao5/uVWPFfurlF18mLtp3ZXzlFntpXk10yy3BQeNr0S1eCrsQTcqPEhnKW/c8kHwNsDH/ISFCI9RtVYz3qGV061Fu3hB/OFe/WmUP9mCng= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=AfTQfBqm; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AfTQfBqm" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1760952469; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ySlbD9JSQ2a30ZVs+aOpmM6Ago5zTLOLY/6GRotx8qU=; b=AfTQfBqmEq5L0A9KjqjVXqSeqrBPIf79F0J/UEl+YVKygvq4EgdRCunko6CF/V/VHPK4Vz d+eriPu0L7kxYR1TQ5Z66reXF0eQ6mU5xIxKWXmo55gB2UERMlOxj/cJ+wH3YHevw3auUp XLUkgQMM0OtkrU/nhIof+NVX6VezNAQ= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-210-BZckTH31Nvyoyxuqngw-yg-1; Mon, 20 Oct 2025 05:27:47 -0400 X-MC-Unique: BZckTH31Nvyoyxuqngw-yg-1 X-Mimecast-MFC-AGG-ID: BZckTH31Nvyoyxuqngw-yg_1760952467 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-471193dacffso26535815e9.2 for ; Mon, 20 Oct 2025 02:27:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760952466; x=1761557266; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=ySlbD9JSQ2a30ZVs+aOpmM6Ago5zTLOLY/6GRotx8qU=; b=Mvm9eumH4kDvxpAK1w7d9gFS6rEoijaNtY/H199Np40Hu5H+MxQBlSDv8TdE+/h3rY SWLqL+vXhgHnPYvZDBsAPb8F10LMdew+D5Xo9tJjG+gQyYj6IW21TXvLbewssR7AdaeL QmHd0uvIjK8N8+A4Ju4Yt1Lt7RdaAlkBChtRhewN3HOcjEZraRbrxyGXUbKQ45WjN3AW QICcDiGsAn1s6ypNSUalc+duS+6YsX/DTzUR7u7qI/N85843magMGLrk/0i5W3KOcAbx H5eI7vfDylHi/u2RmvbiAdvIJuzmk9tFyN2oGxrcq5hjoVx3x0UhmeJS5ComqStY5NQj KrUg== X-Forwarded-Encrypted: i=1; AJvYcCXW/nkfi+kITyDqtZNnQRK0qwatEakLEHQjPcx9+mK1tTCevUBQmuZT0j2uwdl2BSLZYRcAU6Tsrj9eniM=@vger.kernel.org X-Gm-Message-State: AOJu0YzoNaGyZeE+42JtO5UNp8iyIFqlB7LDBxQJoqSBBbTjYzOVcTrE cV/bmPLqToIFP5WIielZVSg0q44PP+2EpxQqTCLFBubFWyDV72+bH2BCWFrN0q/xEM7XTt0q6qe eFGF8Mtnxk16iCB9s/u4thBaSVPgwCoxBWspo2lvgjMxDvYElEReHVRa5j5VUzpLjHA== X-Gm-Gg: ASbGncuqA0j0lDoUGXMU+5eVx4WNHRYvzykRBT6cCEg7auEfsGe3UAwK9k0dgRIQdGL +KsQByH3bH6bfQkTIe2I4wWIRhaKRko76AGNMXMYei6bO5XochWeC+2qfCs+a2VsVQd5Xr4sdBz QJuJIQPe/9NDLYXF1bdxqTc3QWPDmTuvprvy5sbzeptoToc0l0jjccss2N9d9Awtkw3zxniMNzc s5djUDk0scD+2xTyiM2+HXpsbhxdO5HkerE8ceHx1oEwRldtJatRDqxFoDxGiUJwq6Tj2XkRvCP d03P0d2BVa32whtKCqpoCqWKcK7GPq+7NAAEdaMSe/clveH7NBvr+BBLhKjdD6p8AKsKZ8Q92Nn ZrKR1uhHzhy9Q501pOFS9klYsSnZPrzQ= X-Received: by 2002:a05:600c:458b:b0:471:1702:f41a with SMTP id 5b1f17b1804b1-47117919f1bmr98968285e9.33.1760952466509; Mon, 20 Oct 2025 02:27:46 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHUyEeSf/+w1j3kQT+cNvPNRS6yAgY56mxs7wWlFlz2eV2bpnVw6cx7RlqWm7oJTUSvZbsr8Q== X-Received: by 2002:a05:600c:458b:b0:471:1702:f41a with SMTP id 5b1f17b1804b1-47117919f1bmr98968095e9.33.1760952466107; Mon, 20 Oct 2025 02:27:46 -0700 (PDT) Received: from jlelli-thinkpadt14gen4.remote.csb ([176.206.13.103]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-47154d382fesm130481475e9.10.2025.10.20.02.27.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Oct 2025 02:27:45 -0700 (PDT) Date: Mon, 20 Oct 2025 11:27:43 +0200 From: Juri Lelli To: Andrea Righi Cc: Ingo Molnar , Peter Zijlstra , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Joel Fernandes , Tejun Heo , David Vernet , Changwoo Min , Shuah Khan , sched-ext@lists.linux.dev, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 02/14] sched/debug: Stop and start server based on if it was active Message-ID: References: <20251017093214.70029-1-arighi@nvidia.com> <20251017093214.70029-3-arighi@nvidia.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On 20/10/25 11:12, Juri Lelli wrote: > Hi! > > On 17/10/25 11:25, Andrea Righi wrote: > > From: Joel Fernandes > > > > Currently the DL server interface for applying parameters checks > > CFS-internals to identify if the server is active. This is error-prone > > and makes it difficult when adding new servers in the future. > > > > Fix it, by using dl_server_active() which is also used by the DL server > > code to determine if the DL server was started. > > > > Acked-by: Tejun Heo > > Reviewed-by: Andrea Righi > > Signed-off-by: Joel Fernandes > > --- > > kernel/sched/debug.c | 11 ++++++++--- > > 1 file changed, 8 insertions(+), 3 deletions(-) > > > > diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c > > index 6cf9be6eea49a..e71f6618c1a6a 100644 > > --- a/kernel/sched/debug.c > > +++ b/kernel/sched/debug.c > > @@ -354,6 +354,8 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu > > return err; > > > > scoped_guard (rq_lock_irqsave, rq) { > > + bool is_active; > > + > > runtime = rq->fair_server.dl_runtime; > > period = rq->fair_server.dl_period; > > > > @@ -376,8 +378,11 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu > > return -EINVAL; > > } > > > > - update_rq_clock(rq); > > - dl_server_stop(&rq->fair_server); > > + is_active = dl_server_active(&rq->fair_server); > > + if (is_active) { > > + update_rq_clock(rq); > > + dl_server_stop(&rq->fair_server); > > + } > > Won't this reintroduce what bb4700adc3abe ("sched/deadline: Always stop > dl-server before changing parameters") fixed? Ah, OK. It looks like it doesn't, as dl_server_active() is the correct thing to use/check. Also in case the server was not active is should be enqueued in defer mode, so no need to have an updated clock just yet. Reviewed-by: Juri Lelli Thanks, Juri